1. Field of the Invention
This invention relates to an apparatus for connecting end portions of two webs, and more particularly to an apparatus for taking off the web from a web roll comprising a core and the web wound therearound, supplying the same to the succeeding apparatus, and drawing out the web from a new web roll when the web has left from the preceding web roll and connecting the leading end portion of the web on the new web roll to the trailing end of the web drawn out from the preceding web roll.
2. Description of the Related Art
In the conventional cigarette manufacturing process, belt-like paper sheets are wound around cigarette material to form elongated cigarette rods, and thereafter the rods are cut into pieces each having a predetermined length. Similarly, when filters are manufactured in the conventional process, belt-like paper sheets are also wound around filter sheets made of fiber or the like to form elongated filter rods and thereafter the filter rods are cut into pieces each having a predetermined length.
Therefore, continuous supply of the above-mentioned belt-like paper pieces, i.e., webs is required for producing cigarette rods and filter rods. Such a web is usually supplied in a form of a web roll comprising a core and a web wound around a roll, as shown in FIG. 7. The web roll is mounted in a web supplying apparatus and the web is continuously taken off from the web roll and is supplied therefrom to the succeeding apparatus. When the web on the web roll is fully used, a web is taken off from a new web roll and the leading end of the new web is connected to the trailing end of the web from the old web roll. In such a way, webs are supplied continuously.
There has been recently developed a web supplying device which is provided with two web rolls so as to perform these processes automatically. A web is taken off from a first web roll and is supplied to the succeeding apparatus. When the web on the first web roll is fully used, a web is drawn out from the second web roll which was in a waiting state, and the leading end of the web on the second web roll is automatically connected to the trailing end of the web of the first web rib. Thereafter, the core and other necessary parts are removed from the web supplying apparatus, and a new web roll is mounted thereon. With this web supplying device, this series of web supplying and web replacing processes is repeated so that webs are supplied continuously.
The transporting and connecting processes are complicated when using the conventional automatic web connecting device. In order to connect webs, the device requires such a series of complicated processes that the trailing end portion of the web which has already been drawn out is held at an accurate position, the leading end portion of the web newly drawn out is made to overlap with the trailing end portion of the preceding web accurately, both leading and trailing end portions are pressed against each other so as to be connected by an adhesive tape or the like which is disposed therebetween, and the excess portions of the webs are cut.
The mechanisms for performing these processes are collectively arranged on and in the vicinity of the portions of the webs to be connected. Thus, the spaces for admitting these mechanisms are limited. Further, since the webs are flexible and the leading end portion of the newly drawn-out web is made free, special care must be paid to handle them.
In this connection, it is required that the automatic web connecting device have high operational reliability and a simple structure.